The present invention relates generally to orthopedic braces and, more particularly, to orthopedic knee braces.
Orthopedic braces embody a broad range of apparatuses, each having the common purpose of supporting and/or stabilizing a skeletal joint when worn on the body of a user. The orthopedic brace may serve either a preventative role or a remedial role. In a preventative role, the brace provides added support and stability to a healthy skeletal joint, thereby reducing the risk of injury when the joint is subjected to undue stress. In a remedial role, the brace supports and stabilizes a skeletal joint which has been weakened or destabilized by injury, deformity, or other infirmity, thereby reinforcing the joint and providing a therapeutic treatment effect and/or reducing the risk of further injury while the joint is rehabilitated.
Conventional orthopedic knee braces may be generally characterized as frame braces, soft braces, or hybrid braces which include elements of both frame and soft. A frame brace typically has a relatively rigid frame which is secured to the leg of a user by one or more straps engaging the frame and circumscribing the leg. A typical configuration of the frame includes two longitudinal support assemblies which are longitudinally positioned on the opposing medial and lateral sides of the leg respectively. Each longitudinal support assembly includes a relatively rigid upper longitudinal member, a relatively rigid lower longitudinal member and a hinge rotationally connecting the longitudinal members. The hinge of the medial longitudinal support assembly is positioned adjacent to the medial side of the affected knee to be stabilized and the upper and lower longitudinal members engage the medial side of the upper and lower leg above and below the affected knee respectively. The hinge of the lateral longitudinal support assembly is similarly positioned adjacent to the lateral side of the affected knee and the upper and lower longitudinal members engage the lateral side of the upper and lower leg above and below the affected knee respectively.
The typical frame configuration also includes upper and lower cuffs which, like the longitudinal members, are relatively rigid. The upper and lower cuffs are arcuate-shaped to conform to the contours of the upper and lower legs respectively. The upper cuff is attached to and/or integral with the medial and lateral upper longitudinal members and extends orthogonally between the longitudinal members while engaging the anterior or posterior face of the upper leg. The lower cuff is correspondingly attached to and/or integral with the medial and lateral lower longitudinal members and likewise extends orthogonally between the longitudinal members while engaging the anterior or posterior face of the lower leg. In an alternate configuration of the frame, one longitudinal support assembly is omitted from the frame so that only one side of the leg, either the medial or lateral side, has a longitudinal support assembly positioned adjacent to it. Regardless of the particular frame configuration, the frame brace is designed to transfer a substantial fraction of the dynamic and static force loads on the knee to the frame, thereby supporting and stabilizing the knee.
A soft brace differs from a frame brace insofar as the soft brace lacks a frame and overall is relatively less rigid than the frame brace. The soft brace has a compression sleeve which is a tube-like structure formed from a relatively pliant and elastic material that snugly encloses the knee and segments of the upper and lower legs immediately above and below the knee respectively. The sleeve applies radial compression to the knee, thereby supporting and stabilizing the knee. The soft brace may also have one or more straps which engage the sleeve and circumscribe the leg to increase the radially-directed compressive force on the leg at the knee. The support and stabilizing function of the soft brace may be further enhanced by incorporating rigid or semi-rigid stays into the sleeve.
A hybrid brace typically combines the compression sleeve of a soft brace with the longitudinal support assemblies of a frame brace in a single brace. Like the frame brace, the longitudinal support assemblies of the hybrid brace are positioned on the medial and lateral sides of the knee respectively. However, unlike the frame brace, the longitudinal support assemblies are maintained in their desired operative positions alongside the leg by the sleeve, which typically has one or more pockets sewn into its sides to slidably receive and retain the upper and lower longitudinal members of each longitudinal support assembly. As in the case of a frame brace, an alternate configuration of the hybrid brace omits one of the longitudinal support assemblies from the brace so that only one side of the leg, either the medial or lateral side, has a longitudinal support assembly positioned adjacent to it.
Among the conditions destabilizing the knee, which can be mitigated or otherwise treated by using a knee brace, are patellar tracking disorders such as patellar subluxation and dislocation. Patellar subluxation is the undesirable side to side horizontal movement of the patella away from the central trochlear groove as the knee travels back and forth between flexion and extension. Patellar subluxation can cause chronic joint pain when the knee is statically or dynamically loaded and can ultimately lead to dislocation of the patella. Patellar subluxation is believed to be the result of many factors including anatomical irregularities of the knee and/or pelvis and/or an abnormal gait.
Knee braces, which are specifically designed to therapeutically treat patellar tracking disorders, are commonly termed patellofemoral joint tracking knee braces. Exemplary frame knee braces, which are specific to the treatment of patellar tracking disorders, are disclosed in U.S. Pat. Nos. 7,059,329; and 7,905,851. Exemplary soft knee braces, which are specific to the treatment of patellar tracking disorders, are disclosed in U.S. Pat. Nos. 5,759,167 and 7,004,919. An exemplary hybrid knee brace, which is specific to the treatment of patellar tracking disorders, is disclosed in U.S. Pat. No. 7,060,045. All of the above-recited patents are incorporated herein by reference.
Patellofemoral joint tracking knee braces typically treat patellar tracking disorders by directly engaging the side or frontal face of the patella and applying patellar retention forces directly onto the patella with the objective of maintaining the patella longitudinally centered within the trochlear groove when the knee of a user travels back and forth between flexion and extension. When patellar subluxation is in the lateral direction, which is most common, patellofemoral joint tracking knee braces engage the lateral side of the patella and apply retention forces directly onto the patella. Conversely, when patellar subluxation is in the medial direction, which is generally less common, patellofemoral joint tracking knee braces engage the medial side of the patella and apply retention forces directly onto the patella. Although the intent of the laterally or medially directed forces onto the patella is to maintain the patella centered in the trochlear groove as the knee flexes or extends, it is believed that many patellofemoral joint tracking knee braces do not achieve optimal effectiveness for their intended purpose because they impinge on the normal movement and function of the knee. As a result, many patellofemoral joint tracking knee braces do not effectively treat and stabilize knees which exhibit patellar tracking disorders.
The present invention recognizes the need for an alternate patellofemoral joint tracking knee brace which has a more effective patellar tracking disorder treatment function relative to conventional patellofemoral joint tracking knee braces known in the prior art. Accordingly, it is generally an object of the present invention to provide a patellofemoral joint tracking knee brace which satisfies the above-recited need. This object and others are accomplished in accordance with the invention described hereafter.